1. Field of the Invention
This invention relates to containers for compressed gases, and more particularly for containers which may be carried on a person and which may be used for other purposes such as containers for compressed gas for use in vehicles or other applications having weight and space constraints.
2. Related Art
Divers, fire fighters, miners and alike must perform numerous tasks which require that they carry a portable supply of compressed gases. These gases are usually for breathing in unbreathable environments; however, other gases such as carbon dioxide which are used for extinguishing fires are also carried.
Conventional containers for this purpose are normally of a cylindrical shape with domed ends, and construction is usually of steel or aluminum, or glass fiber wound aluminum. Unfortunately, these containers are cumbersome to wear due to their bulky shape, their rigid structure and their relatively heavy weight. As a result, wearers have difficulty moving in confined spaces, are uncomfortable and are subject to increased levels of fatigue.
Prior approaches such as seen in Pat. No. 3,338,238 involves a complex, multicell container which can be made in a relatively flat, oval-shape cross section. However, these containers are difficult to manufacture and do not conform to the shape of the wearer.
Pat. No. 3,491,752 illustrates a slightly flexible pressure vessel made in the form of a coiled spiral tube. This vessel is compact and light weight, but ineffective if more than several minutes of breathing gases are required. While the storage capacity of such a pressure vessel could be increased by using either larger diameter tube or thicker walled tube, the changes are impractical since tubing of increased dimension would not easily coil into a compact shape. Pat. No. 3,432,060, to the same inventor has similar deficiencies.
Pat. No. 1,288,857 illustrates a life preserver with a plurality of closed cylinders constructed of rubber, rubber cloth or other suitable air tight fabric, the cylinders being connected together by smaller tubes which are preferably integral with the cylinders. However, the shape, size, and requirement for connecting pipe sections make the unit expensive to manufacture. Further, because of the need for connecting tubes, etc., it cannot be as compact as desirable for personal use.
Pat. No. 2,380,372 illustrates a flexible, portable container designed to be built into the seat of a parachute that is part of a parachute pack in order to provide oxygen to parachutists. The container includes a length of pipe made in the form of a flat coil, the outer turns of which conform generally to the shape of the seat. The coil of pipe is in the form of a coil in ever decreasing rectangles, squares, or circles which are concentric.
Pat. No. 1,608,267 is another older patent which has a life-ring worn around the waist of a user and has a supply of air therein.
German Patent No. 971,689, issued in 1959, includes a plurality of parallel metal cylinders, connected to succeeding cylinders by means of small metal tubes. This particular device is obviously expensive to make and very heavy to use by a wearer or in industrial applications.
It will be appreciated that the prior types of portable containers had the following disadvantages:
1. If the containers hold more than a few minutes worth of breathing gases, they are large in size and protrude a great distance from the wearer's body.
2. Containers in use at the present time are heavy.
3. The manufacture of existing containers is complex and costly.
4. In the area of compressed natural gas (CNG) containers used, for example in conjunction with automotive vehicles, the containers must be relatively large cylinders or spheres which occupy an inordinate amount of space.